Hot starting problem

[flattopwill]

02 5.3 L59 DBW. It starts fine when cold but when I try to start it while warmed up it fires and then dies as if the ignition was cut. Then when I try again it kinda gurgles and has a hard time starting. If I give it a little throttle while I start it it does fine.

I tested fuel pressure at the rail and it is sufficient. It does not bleed off quickly when the truck is shut off and the truck will have a problem starting even while fuel pressure is still up.


Any ideas?

[RedHeartbeat]

my 08 does that too after the engine swap. I just crack the throttle a little and no issue. Mine must be due to swapping the injectors out. My FP is about 70 PSI with hot engine off after 5 minutes, too high IMO. When you try to start it the engine get flooded with fuel because of the excess fuel pressure. I'm tempted to put a FPR or corvette fuel filter on it to regulate it at 58 PSI at all times.

[flattopwill]

Wow that is a lot of fuel pressure! Mine only gets about 45psi and I was told since it is a flex fuel motor that is normal.

[96/chevy/pu]

On the stock truck I would check to make sure throttle blade is clean of carbon if so give the throttle screw a half turn or so. Minimum idle is affected by carbon (clean it) and also over time bushing wear slightly causing the blade to close tighter so simply give the idle screw a twist. Oh and that plug that covers the screw is no big deal to get out just take a ice pick to the center of the cap punch it then just lean the pick over causing the plug too come out or the pick to break.

BB

[flattopwill]

i didnt know there was an idle screw on a dbw tb? well this is pretty annoying especially when you are tryin to show off your new motor to your friends. They ask me how its runnin and im like oh ya its running great then it starts and dies. real nice.

[96/chevy/pu]

oops my bad didn't see the DBW bit, still wouldn't hurt to Ck too see if carbon is built up on plate though

[foggy]

you need to make adjustment in your startup airflow table in the tune.

[flattopwill]

you need to make adjustment in your startup airflow table in the tune.

Nelson did my tune?

[foggy]

give him a call and let him know what it is doing.

[flattopwill]

grrr